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Discussion Starter · #1 ·
I ordered a 16 Ohm speaker from Lionel to correct an issue with my Legacy H10 sound system. The speaker I order was part # 691-1209-536. When you look at the picture on their web site it shows a single speaker yet what I received was two speakers connected by a harness with a mini-connector.

The speakers are marked 16 Ohm 2 w. I was told that they had to be used together otherwise they would in fact only be 8 Ohm and might possible damage the sound board.

Now the H10 is not designed to have twin speakers on a single speaker. Now another speaker I ordered was Part # 691-1209-536 which a 2 “ Fatboy speaker. I’m planing on using it if it will fit into the tender and be an exact replacement for the existing speaker. If you try to look up the part number it does not come up properly and you need to request ”see all” and then scan down to find it.

So, any ideas?
 

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Are the speakers themselves marked 16 ohms or is the package marked 16 ohms. Whatever is on the speaker itself is what the impedance is. You can verify with an ohmmeter. It will read 10-20% less than what it says. Speaker impedance is nominal which means it varies over the frequency range.
i would think you need a single 8 ohm speaker in that engine. Dual 16 ohm speakers wired in parallel are used in a few large diesels and steam tenders.

Pete
 

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Discussion Starter · #3 ·
Pete,

Thanks for the reply. Yes they are both marked 16 Ohm and connected by a harness with a molex connector. I’m sure they were designed for a dual speaker application.

You’re right the current speaker in that engine is 8 Ohms. Lionel made a programming mistake on these engines that would cause the sound system to overload if the volume was set too high and shut down if you blew the whistle. Lionel was making the necessary programming to eliminate the problem under warranty but I never knew that.

So the recommendation is to install a 16 Ohm speaker and that will resolve the issue. As I mentioned I bought another speaker part # 691-1209-536 which is a 2 “ Fatboy speaker and if it fits I’ll just go with that one and sell the others. If not I’ll check out the other speakers and if one of them is a better fit I’ll use that one.
 

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Another option is just turn the volume down with the pot assuming you have a pot. Lionel Railsounds is designed for 8 ohm speakers. If your RS board as not failed yet just set the pot at halfway with the existing speaker in place. FWIW I am using a 4 ohm speaker in an MTH engine designed for 16 ohms. Don’t try this at home.
Common wisdom says the amp will explode. I just turn the volume down using the handheld but if I want to impress other MTH owners I jusy crank the volume to max. The bass blows away any other MTH engine and I have run it for ten minutes that way, no problem. Otherwise volume is down.
Another bodge repair by Lionel telling you to replace the speaker with a 16 ohm.

Pete
 

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Discussion Starter · #6 ·
Sorry both speakers are 40mm. However one is marked Fatboy and the ones that are twins are not. I’m going to just sell the other ones since I don’t need them.
 

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Another option is just turn the volume down with the pot assuming you have a pot. Lionel Railsounds is designed for 8 ohm speakers. If your RS board as not failed yet just set the pot at halfway with the existing speaker in place. FWIW I am using a 4 ohm speaker in an MTH engine designed for 16 ohms. Don’t try this at home.
Common wisdom says the amp will explode. I just turn the volume down using the handheld but if I want to impress other MTH owners I jusy crank the volume to max. The bass blows away any other MTH engine and I have run it for ten minutes that way, no problem. Otherwise volume is down.
Another bodge repair by Lionel telling you to replace the speaker with a 16 ohm.

Pete
There's no permanent failure of the RS-Lite board in the Legacy H10 if it cuts out, it has an overload protection circuit that shuts down the audio amp if it gets over temperature, and restores it once it's within limits again. The 16 ohm speaker ends up accomplishing the same thing as the Lionel reprogramming, and then you don't have to tinker with the volume.

Your example of the 5V PS/2 board doesn't really offer a lot of risk either, that amplifier is protected from short circuits or overloads across the output.

From the TDA7056A Amplifier Datasheet.
Organism Rectangle Font Technology Magenta
 

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So if it ain’t broke, don’t fix it. All other things being equal a 16 ohm driver will not be as loud as an 8 ohm speaker assuming you are replacing a 8 ohm baby fatboy with a 16 ohm baby fatboy.

Pete
 

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So if it ain’t broke, don’t fix it. All other things being equal a 16 ohm driver will not be as loud as an 8 ohm speaker assuming you are replacing a 8 ohm baby fatboy with a 16 ohm baby fatboy.

Pete
You want an 8 ohm speaker. Two 16 ohm speakers wired in parallel is also good - the amp sees an 8 ohm load.
 

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Mike,I designed speaker systems professionally. TJ is the one looking for a replacement. I offered my solution, turn the volume down. No need to make a mountain out of mole hill.

Pete
 

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Mike,I designed speaker systems professionally. TJ is the one looking for a replacement. I offered my solution, turn the volume down. No need to make a mountain out of mole hill.

Pete
Sorry, I wasn't sure which solution was at currently at the forefront - f the OP was still pondering which speaker to use. You suggested both.

Familiar with Response Modeler, PCD, WinISD, etc. I've used them to relace the woofer with a modern driver in original advents ('69 version) while retaining the "fried egg". And built a 2.1 portable for beach dances along side the Atlantic with a 8", 4 ohm Scanspeak woofer ...
 

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Mike,
Hmm. I’d be interested to know exactly which woofers/drivers you put in those Advents. I have 4 of the originals too. One pair minus the woofers. Other set reconed in 2004.

KW
 

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Mike,
Hmm. I’d be interested to know exactly which woofers/drivers you put in those Advents. I have 4 of the originals too. One pair minus the woofers. Other set reconed in 2004.

KW
I wouldn't recommend it. I used 12" woofers so they became very directional. And I modified the XO. I found out after the fact that the woofer mfg. had bogus driver parameters. I had to use a dedicated amp with low frequency dropout to correct for a huge bass hump below 80 hz. I'm sure some teens would love them :)

There's the generic "replacement" woofers all over the net. While they may not be exactly like the originals, they seem to be the right type of woofer for the Advents' sealed box. Let me ask in my other forum and I'll get back to you.
 

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Mike,
Hmm. I’d be interested to know exactly which woofers/drivers you put in those Advents. I have 4 of the originals too. One pair minus the woofers. Other set reconed in 2004.

KW
One way to try and find a suitable replacement is remove the existing woofer and try and get a accurate measurement of volume inside the box. Then using the Thiele/Small parameters look for as many drivers that size that are close. Finally narrowing down those by reputation and feedback.

I was doing this stuff thirty years ago. I had a 10 band spectrum analyzer with a calibrated mike. Later started programming in National Instruments Labview software which gave a much more detailed transform using that mike. Pretty much out of touch with what available today. I assume there are low cost or freeware tools available today to do this.

Pete
 

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One way to try and find a suitable replacement is remove the existing woofer and try and get a accurate measurement of volume inside the box. Then using the Thiele/Small parameters look for as many drivers that size that are close. Finally narrowing down those by reputation and feedback.

I was doing this stuff thirty years ago. I had a 10 band spectrum analyzer with a calibrated mike. Later started programming in National Instruments Labview software which gave a much more detailed transform using that mike. Pretty much out of touch with what available today. I assume there are low cost or freeware tools available today to do this.

Pete
Never got into measurements with a mic, etc.

I had a need to develop a serious beach boombox in 2015: something beyond anything commercially available. I found Parts Express's Tech Talk forum and some likable gents there "sucked me in". I learned to use all the modern S/W they had to design speaker systems. I evaluated over 50 woofers using WinISD (Thiele/small) to find one with the right combination of efficiency, box size and F3 for the beach. I turned out a box that amazed me as well as well all my beach buddies; 140 W rms with an f3 of 41 Hz. Then I tried my hand at the Advents I found on the side of the road with blown Radio Shack woofers using measurement graphs taken long ago of the "Fried Egg".

I had to relearn math I forgot from high school to relearn math I forgot from college to calculate active filter designs (Sallen-Key) for the small, "digital" amps I was using for the box. Became kind of the resident expert on TT for those amps gents were using some systems. Some modifications I made to Parts Express products made it back to the mfg.'s and into the products.

Then I gave up the hobby, my need fulfilled
.
 

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Okay, the gents at Tech Talk are very familiar with the Advents. The original woofer has some odd characteristics designed specifically for the box (and the era). If you use an off-the-shelf woofer, you'll need to modify the crossovers (as I did). They're saying your best best bet is a refoam kit or refoam service on the original woofers.

You can Try Here for a service, or Here for a kit.
 

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Advents, AR’s, and KLH were all developed by Henry Kloss. The idea behind acoustic suspension speakers is you use a floppy surround and used the air in the sealed box as the spring. Again, I have been out if touch for years but it makes sense you would be better off replacing the surround rather than trying to find a similar driver new. I used to have a pair of AR5s which had the foam surround deteriorate. Thats when I started building my own.
Pete
 
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